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The first crystal structure of human RNase 6 reveals a novel substrate-binding and cleavage site arrangement
- Source :
- Biochemical Journal, Dipòsit Digital de Documents de la UAB, Universitat Autònoma de Barcelona
- Publication Year :
- 2016
- Publisher :
- Portland Press Ltd., 2016.
-
Abstract
- We describe the first human RNase 6 crystal structure in complex with sulfate anions. Kinetic analysis, site-directed mutagenesis and molecular dynamics simulations identified novel substrate recognition and cleavage sites.<br />Human RNase 6 is a cationic secreted protein that belongs to the RNase A superfamily. Its expression is induced in neutrophils and monocytes upon bacterial infection, suggesting a role in host defence. We present here the crystal structure of RNase 6 obtained at 1.72 Å (1 Å=0.1 nm) resolution, which is the first report for the protein 3D structure and thereby setting the basis for functional studies. The structure shows an overall kidney-shaped globular fold shared with the other known family members. Three sulfate anions bound to RNase 6 were found, interacting with residues at the main active site (His15, His122 and Gln14) and cationic surface-exposed residues (His36, His39, Arg66 and His67). Kinetic characterization, together with prediction of protein–nucleotide complexes by molecular dynamics, was applied to analyse the RNase 6 substrate nitrogenous base and phosphate selectivity. Our results reveal that, although RNase 6 is a moderate catalyst in comparison with the pancreatic RNase type, its structure includes lineage-specific features that facilitate its activity towards polymeric nucleotide substrates. In particular, enzyme interactions at the substrate 5′ end can provide an endonuclease-type cleavage pattern. Interestingly, the RNase 6 crystal structure revealed a novel secondary active site conformed by the His36–His39 dyad that facilitates the polynucleotide substrate catalysis.
- Subjects :
- 0301 basic medicine
RNase P
Molecular Sequence Data
Molecular dynamics
Crystallography, X-Ray
Biochemistry
RNase PH
Catalysis
Protein Structure, Secondary
Kinetic characterization
Substrate Specificity
03 medical and health sciences
sulfate anion
protein crystallography
Hydrolase
Humans
Amino Acid Sequence
Binding site
RNase H
Molecular Biology
kinetic characterization
Research Articles
Binding Sites
biology
Sequence Homology, Amino Acid
Protein crystallography
Active site
Cell Biology
Ribonuclease, Pancreatic
molecular dynamics
RNase A superfamily
RNase MRP
Kinetics
030104 developmental biology
Polynucleotide
biology.protein
Sulphate anion
RNase k6
Research Article
Protein Binding
Subjects
Details
- Language :
- English
- ISSN :
- 14708728 and 02646021
- Volume :
- 473
- Issue :
- 11
- Database :
- OpenAIRE
- Journal :
- Biochemical Journal
- Accession number :
- edsair.doi.dedup.....6a5014e3875b65b39b7c04f569d1e66e